The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7ebb82306f1eddf25a3172e339c2ecd1a331d741

commit 7ebb82306f1eddf25a3172e339c2ecd1a331d741
Author: Carlos Knippschild <carlosk@chromium.org>
Date: Thu Mar 22 20:59:42 2018

Add feature flag for opening offline pages in CCT

Bug:  824807 
Change-Id: I4004692e55281fc95dd548911c529614017b6a02
Reviewed-on: https://chromium-review.googlesource.com/974750
Commit-Queue: Carlos Knippschild <carlosk@chromium.org>
Reviewed-by: Justin DeWitt <dewittj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#545245}
[modify] https://crrev.com/7ebb82306f1eddf25a3172e339c2ecd1a331d741/chrome/browser/about_flags.cc
[modify] https://crrev.com/7ebb82306f1eddf25a3172e339c2ecd1a331d741/chrome/browser/flag_descriptions.cc
[modify] https://crrev.com/7ebb82306f1eddf25a3172e339c2ecd1a331d741/chrome/browser/flag_descriptions.h
[modify] https://crrev.com/7ebb82306f1eddf25a3172e339c2ecd1a331d741/components/offline_pages/core/offline_page_feature.cc
[modify] https://crrev.com/7ebb82306f1eddf25a3172e339c2ecd1a331d741/components/offline_pages/core/offline_page_feature.h
[modify] https://crrev.com/7ebb82306f1eddf25a3172e339c2ecd1a331d741/components/offline_pages/core/offline_page_feature_unittest.cc
[modify] https://crrev.com/7ebb82306f1eddf25a3172e339c2ecd1a331d741/tools/metrics/histograms/enums.xml

A few comments about the OP-in-CCT behavior:
* The security chip and address bar are still there, as expected and desired, but have a slightly different presentation (see attached image).
* The open-online-version snackbar does appear and tapping on its action opens the online page in the CCT (I will still look into trying to change that).
* If Chrome is force-closed the CCT or Downloads Home are not restored upon restart (when opened in tabs, as expected, the tab is restored to the previously opened offline page). This means that to get back to where they were, the user has to re-open the DH and re-open the offline page.

Deleted: Screenshot_20180327-133746.png 574 KB

	Screenshot_20180327-133746.png 574 KB View Download

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0b1b7baa4695c945a1b0bea1f0636f1219139e8e

commit 0b1b7baa4695c945a1b0bea1f0636f1219139e8e
Author: Carlos Knippschild <carlosk@chromium.org>
Date: Wed Mar 28 18:06:50 2018

Open Offline Pages in CCT from Downloads Home.

When the respective feature flag is enabled, offline pages opened from
the Downloads Home will use CCT instead of normal tabs.

Bug:  824807 
Change-Id: I6d968b8b0c51aaeb7f26332c7ada9f927e151a65
Reviewed-on: https://chromium-review.googlesource.com/977321
Commit-Queue: Carlos Knippschild <carlosk@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Reviewed-by: Bernhard Bauer <bauerb@chromium.org>
Reviewed-by: Jian Li <jianli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#546545}
[modify] https://crrev.com/0b1b7baa4695c945a1b0bea1f0636f1219139e8e/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/downloads/OfflinePageDownloadBridge.java
[modify] https://crrev.com/0b1b7baa4695c945a1b0bea1f0636f1219139e8e/chrome/browser/offline_pages/android/downloads/offline_page_download_bridge.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4602305fcc25d1a9246e98cd34ec38663c12417c

commit 4602305fcc25d1a9246e98cd34ec38663c12417c
Author: Carlos Knippschild <carlosk@chromium.org>
Date: Wed Apr 04 23:53:08 2018

Add custom CCT UI settings for presenting offline pages

Offline pages need a custom version of the menu items shown by CCT. This
change creates a custom UI type for presenting offline pages that
properly configures the menu and also disables the "powered by Chrome"
footer.

Bug:  824807 
Change-Id: Ic20f03ee152b8f538161810e87bc0e514886a3e7
Reviewed-on: https://chromium-review.googlesource.com/996395
Reviewed-by: Jian Li <jianli@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Commit-Queue: Carlos Knippschild <carlosk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548255}
[modify] https://crrev.com/4602305fcc25d1a9246e98cd34ec38663c12417c/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabAppMenuPropertiesDelegate.java
[modify] https://crrev.com/4602305fcc25d1a9246e98cd34ec38663c12417c/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabIntentDataProvider.java
[modify] https://crrev.com/4602305fcc25d1a9246e98cd34ec38663c12417c/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/downloads/OfflinePageDownloadBridge.java
[modify] https://crrev.com/4602305fcc25d1a9246e98cd34ec38663c12417c/chrome/android/javatests/src/org/chromium/chrome/browser/customtabs/CustomTabActivityTest.java

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0ed4c99b4e45699075e38cc6c27d9f4f763f25b5

commit 0ed4c99b4e45699075e38cc6c27d9f4f763f25b5
Author: Carlos Knippschild <carlosk@chromium.org>
Date: Tue Apr 10 00:15:56 2018

Fixed offline page opening in CCT when not from DH.

With the open-in-CCT flag enabled, offline pages should only open in CCT
if they are being launched from the downlaods home. Alas they were being
opened that way from the download finished snackbar as well.

This CL fixes that by checking that the current activity is indeed the
DH.

Bug:  824807 
Change-Id: Ia5f895c7fd7bbb277f8b614c1db44ec19c2da85a
Reviewed-on: https://chromium-review.googlesource.com/998832
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Commit-Queue: Carlos Knippschild <carlosk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#549337}
[modify] https://crrev.com/0ed4c99b4e45699075e38cc6c27d9f4f763f25b5/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/downloads/OfflinePageDownloadBridge.java

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2c76efa259c846498b011e7722a80f2ed7570ed4

commit 2c76efa259c846498b011e7722a80f2ed7570ed4
Author: Carlos Knippschild <carlosk@chromium.org>
Date: Sat May 19 00:35:30 2018

Add fieldtrial entry for OfflinePagesInDownloadHomeOpenInCct

Bug:  824807 
Change-Id: Id519f094a1683fc62d29545ed190684c81675d05
Reviewed-on: https://chromium-review.googlesource.com/1063551
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Commit-Queue: Carlos Knippschild <carlosk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#560120}
[modify] https://crrev.com/2c76efa259c846498b011e7722a80f2ed7570ed4/testing/variations/fieldtrial_testing_config.json

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b177e8b5ae8b830a0dc97ddfca0ed0602f60d07e

commit b177e8b5ae8b830a0dc97ddfca0ed0602f60d07e
Author: Carlos Knippschild <carlosk@chromium.org>
Date: Thu Jun 28 00:53:05 2018

Enable by default opening offline pages in CCTs from the DH

Bug:  824807 
Change-Id: Iaec899173324ad82ce702406077f3664b7db8e57
Reviewed-on: https://chromium-review.googlesource.com/1117746
Reviewed-by: Dmitry Titov <dimich@chromium.org>
Commit-Queue: Carlos Knippschild <carlosk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570985}
[modify] https://crrev.com/b177e8b5ae8b830a0dc97ddfca0ed0602f60d07e/components/offline_pages/core/offline_page_feature.cc
[modify] https://crrev.com/b177e8b5ae8b830a0dc97ddfca0ed0602f60d07e/components/offline_pages/core/offline_page_feature_unittest.cc

This is now enabled via experiment configuration for M67+ to 99% of Stable (1% control group will still kept for a few months) and will be enabled by default in code as of M69.